School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
Macromol Rapid Commun. 2021 Jul;42(14):e2100174. doi: 10.1002/marc.202100174. Epub 2021 May 5.
Nonconventional luminescence polymers without any aromatic structures have attracted great interest from researchers due to their special structure and excellent biocompatibility. However, these materials mostly emit in the blue or green region, in which preparation of materials with long-wavelength (especially near-infrared) emission is still a great challenge. In this work, it is found that 2-(dimethyl amino) ethyl methacrylate (DMA) and itaconic anhydride (ITA) undergo a ring-opening reaction at room temperature, and subsequently generate zwitterionic compound (IDMA). Based on the clustering-triggered emission (CTE) mechanism, ionic bond can effectively promote the isolated electron-rich chromophores to form new emissive clusters with extended electron delocalization. Herein, two oligomers (P1 and P2) with different fluorescence emissions by controlling the concentration of zwitterionic monomers before polymerization are synthesized. It is worth noting that the maximum emission wavelength of P2 at high concentration is up to 712 nm, which is very rare in previous reports. In addition, the resulting oligomer (P2) shows typical aggregation-enhanced emission (AEE), excitation-dependent fluorescence, temperature-sensitive emission, and solvatochromism. The cytotoxicity assay demonstrates that P2 was low toxic to Huh7 and LM3 cells, and suitable for cell imaging. This research provides the possibility for rational molecular design and the feasibility of luminescence regulation.
无芳香结构的非传统发光聚合物因其特殊的结构和优异的生物相容性而引起了研究人员的极大兴趣。然而，这些材料大多在蓝色或绿色区域发射，其中长波长（特别是近红外）发射材料的制备仍然是一个巨大的挑战。在这项工作中，发现 2-（二甲氨基）乙基甲基丙烯酸酯（DMA）和衣康酸酐（ITA）在室温下开环反应，随后生成两性离子化合物（IDMA）。基于聚集诱导发光（CTE）机制，离子键可以有效地促进富电子生色团形成具有扩展电子离域的新发光团簇。本文通过控制聚合前两性离子单体的浓度，合成了两种具有不同荧光发射的低聚物（P1 和 P2）。值得注意的是，P2 在高浓度下的最大发射波长高达 712nm，这在以前的报道中是非常罕见的。此外，所得低聚物（P2）表现出典型的聚集增强发光（AEE）、激发依赖性荧光、温度敏感发射和溶剂变色性。细胞毒性试验表明，P2 对 Huh7 和 LM3 细胞的毒性较低，适合细胞成像。该研究为合理的分子设计和发光调控提供了可能性。
